Interstitial cystitis (IC) is a chronic inflammatory condition of the bladder of unknown etiology. Interstitial cystitis can affect people of any age, race or sex, however, IC is most commonly found in women. Recent epidemiological data suggest that there may be greater than 700,000 cases of IC in the US alone.
Interstitial cystitis is characterized by irritative voiding symptoms, symptoms of urinary urgency, frequency, dysuria, nocturia, and suprapubic or pelvic pain related to and relieved by voiding. “Common” cystitis, also known as a urinary tract infection, is caused by bacteria and is usually successfully treated with antibiotics. Unlike common cystitis, IC is generally believed not to be caused by bacteria and does not respond to conventional antibiotic therapy. It is important to note that IC is not a psychosomatic disorder nor is it believed to be caused by stress.
Symptoms or clinical signs of interstitial cystitis (IC) can include: 1) frequency of urination (whether day or night) the frequency of urination can be up to 60 times a day in severe cases. In early or very mild cases of IC, frequency of urination is sometimes the only symptom; 2) urgency of urination, i.e., the sensation of having to urinate immediately, which may also be accompanied by pain, pressure or spasms.; 3) pain which can be in the lower abdominal, urethral or vaginal area. Pain is also frequently associated with sexual intercourse. Men with IC may experience testicular, scrotal and/or perineal pain, and painful ejaculation; and 4) other disorders, e.g., some patients also report muscle and joint pain, migraines, allergic reactions, gastrointestinal problems and skin problems as well as the more common symptoms of IC described above. It appears that IC has an as yet unexplained association with certain other chronic diseases and pain syndromes such as vulvar vestibulitis, fibromyalgia and irritable bowel syndrome. Many IC patients, however, have only bladder symptoms.
Symptoms of IC are usually present for many years before diagnosis and they usually peak and stabilize within a few years of diagnosis. Progression of the disease often leads to social and emotional crippling. The pain and frequency may interfere with an individual's ability to work and to socialize, and the nocturia may lead to chronic loss of sleep.
The prevalence in some IC patients of headaches, gastrointestinal and skin problems may tend to suggest that interstitial cystitis may represent the end organ (bladder) response of a systemic condition affected by many heterogeneous stimuli triggering a common denominator, e.g., the mast cell. However, the pathology and pathogenesis of IC have not been clearly elucidated. Proposed theories include infection, vascular obstruction, autoimmunity, inflammatory, neurogenic and endocrine causes.
The role of the mast cell in the bladder wall and the bladder surface protective glycosaminoglycan (GAG) layer are areas of research interest. Research indicates that mast cells in the bladder may be activated in IC without necessarily increasing the total numbers of cells. Histamine and other mediator release in the bladder wall of IC patients may be a pathogenetic mechanism for the causation of the disease. It is uncertain whether the mast cell is a consequence of IC or a pathogenetic factor in its causation.
Most IC patients have difficulty in obtaining a definitive diagnosis of IC. To make a proper diagnosis of IC, a urologist will typically: 1) obtain a urine culture to determine if there is a bacterial infection present; 2) rule out other diseases and/or conditions that have symptoms resembling IC. These diseases may include bladder cancer, kidney problems, tuberculosis, vaginal infections, sexually transmitted diseases, endometriosis, radiation cystitis and neurological disorders; and 3) perform a cystoscopy with hydrodistention under general anesthesia if no infection is present and no other disorder is discovered. If distention under anesthesia is not performed, the diagnosis of IC may be missed. Cystoscopy during a routine office visit may not reveal the characteristic abnormalities of IC and can be painful for those who have IC. Therefore, it is necessary to distend the bladder under general or regional anesthesia in order to see the pinpoint hemorrhages on the bladder wall that are essentially pathopneumonic for this disease. In some cases, a biopsy of the bladder wall may be necessary to rule out other diseases such as bladder cancer and to assist in the diagnosis of IC because IC is not usually associated with bladder cancer.
Currently, there is no cure for IC, nor is there an effective treatment which works for everyone. Prior to the present invention treatments have been aimed at a variety of therapeutic regimens including, oral medications, bladder instillations, diet regulation, nerve stimulation, and/or surgery. ELMIRON® (pentosan polysulfate sodium) received FDA approval in 1996 and is the only oral medication approved specifically for use in IC. It is believed to work by repairing a thin or damaged bladder lining (See e.g., U.S. Pat. No. 5,180,715, to Parsons which discloses a method of treating bladder infections, IC and tumors in mammals comprising the oral administration of sodium pentosanpolysulfate at high dosages on the order of 200 mg. per day or more). Also disclosed is a method comprising irrigation of the internal bladder and associated surfaces with an irrigating solution containing an effective amount of sodium pentosanpolysulfate.
Other oral medications that have been used in the treatment of IC include tricyclic antidepressants such as Elavil® (amitriptyline) which has been shown to help with both the pain and frequency of IC. In IC, these medications are used for their anti-pain properties, not as a treatment for depression. Other oral medications include anti-inflammatory agents, antispasmodics, bladder analgesics, such as Urimax®, antihistamines, and muscle relaxants. For example, U.S. Pat. No. 5,994,357, to Theoharides discloses a method of treating patients suffering from IC comprising the administration of an inhibitor of neurohormonal activation of mast cell secretion e.g., a histamine-1 receptor antagonist consisting of azatadine, azelastine, cetirizine, hydroxyzine and ketotifen, by oral, parenteral, transmucosal, and transdermal routes of administration.
Another method of treatment of IC comprises a regimen of bladder instillations or bladder distention with various therapeutic agents. In bladder distention, the bladder is stretched by filling it with water under general anesthesia. This is part of the diagnostic procedure for IC, and may be therapeutic as well. DMSO (dimethyl sulfoxide) is a medication that is sometimes instilled directly into the bladder. DMSO is believed to work as an anti-inflammatory agent and therefore reduces pain. DMSO can be mixed with steroids, heparin, and/or local anesthetics to form a bladder “cocktail.”
BCG (bacillus Calmette-Guerin) mycobacterium bovis derived immune stimulant is an instillation agent that is an experimental treatment currently in the clinical phrase and is not yet approved for IC by the FDA. It is, however, approved for the treatment of bladder cancer and it appears to work by boosting the immune system. CYSTISTAT® (hyaluronic acid) is another instillation product that is in clinical trials and is not yet approved for use in IC in the United States. It is thought to work by replacing the defective lining of the bladder with a coating of hyaluronic acid. For example U.S. Pat. Nos. 5,591,724; 5,880,108; and 5,888,986 to Morales et al. disclose methods of treating IC comprising contacting the internal bladder and associated structures in a mammal having interstitial cystitis with a solution containing hyaluronic acid.
Other infusion therapies include, e.g., U.S. Pat. No. 6,083,933 to Hahn which discloses a method of treatment of cystitis of the bladder and urinary tract, particularly interstitial cystitis, using effective unit doses of chondroitin sulfate. Cystitis patients are screened for their response to a given cystitis treatment using a method in which patients are first challenged with an irritant and then treated with a selected cystitis therapeutic such as chodroitin sulfate. Likewise, Clorpactin WCS-90 (oxychlorosene sodium), has been tried as an instillation agent, however, its use can be very painful and requires general anesthesia. Silver Nitrate is also used infrequently and is now considered an outdated therapy.
Other therapeutic measures include diet. The elimination of certain foods (acidic, spicy) may decrease the severity of IC symptoms. Also, smoking, drinking coffee or tea, and alcoholic beverages may aggravate IC. Prelief, an over-the-counter dietary supplement, has also been tired to help IC patients better tolerate acid foods and beverages.
Self-help techniques may improve the quality of life and reduce the incidence and severity of flare-ups of IC. These include changes in diet, stress reduction, visualization, biofeedback, bladder retraining and exercise, among others. Electronic nerve stimulators, e.g., Transcutaneous Electrical Nerve Stimulation (TENS) have also been tried as a therapeutic to combat IC. This device, which is worn externally, has been shown to relieve bladder pain in some people. Sacral Nerve Stimulation Implants are surgically implanted devices that are approved for use in treating urinary incontinence, urgency and frequency. They are not yet FDA-approved for treating IC pain, but are currently undergoing testing for this purpose.
For a small minority of patients whose symptoms are severe and who do not respond to other IC treatments, bladder surgery may be considered. However in some cases, IC symptoms may not improve. Several types of surgery have been used to treat IC, including cystectomy and urinary diversion. Laser surgery has been reserved solely for the Hunner's ulcer form of IC.
Although the above-mentioned therapeutic measures have met with varying degrees of success, there still remains a need in the art for a simple, safe and effective treatment and/or preventative for IC and its sequella which will relieve and/or prevent the devastating effects of the complicated and poorly understood IC disease process.
More importantly, prior to the present invention there has not been a single effective composition specifically formulated for use as a medical device for direct bladder installation that combines an optimal combination of active agents which can be used for instillation therapy in the treatment of IC. In particular, there exists a need in the art for a composition formulated for direct bladder installation use that uniquely combines synergistically active agents for use in a method of treatment of IC or related urinary tract conditions in man and in animals.
Likewise, prior to the present invention there has not been a single effective composition specifically formulated for parenteral (e.g., intravenous or intramuscular) use which combines an optimal combination of active agents which can be used for intra-parenteral treatment of IC. In particular, there exists a need in the art for a composition formulated for parenteral or other systemic use which combines synergistically active agents to treat and/or prevent IC and/or related urinary tract conditions in man and in animals.